The present invention relates to the field of optics, particularly X-ray optics, and microelectronics. More particularly, the present invention relates to laser pulse vapor deposition (LPVD) of thin and very thin layers on a substrate.
According to WP C 23 C/338 176 8 DD, a target having a curved surface is exposed to a laser beam which is fixed in position. The target having the curved surface is displaced from a center position X.sub.0 along an X axis in uniform steps .DELTA.X in both directions on the X axis so that a plasma plume generated when the pulsed laser beam strikes the target and propagated in a radial direction from the curved target can brush over the surface of a substrate positioned near the target. The target is also displaced along a Y axis so that the entire surface of the substrate is exposed to a maximum intensity of the plasma plume.
The disadvantages of this above-described prior art method include formation of a deposited layer on the substrate having a non-uniform thickness, since the deposition rate on a portion of the substrate surface positioned opposite the center of the target is greater than on those portions of the substrate surface opposite the edge regions of the target, and also because of a change in target curvature due to irregular target cutting by the pulsed laser beam. The reason for both of the latter effects is that the laser beam output density at the target changes as a function of the displacement of the target from the center position X.sub.0. This change in the laser beam output density at the target is due to the increase in size of the target surface area element where the pulse laser beam impinges due to target surface curvature as the displacement from the center position X.sub.0 increases.